I share your frustration with this implementation (my participation in this endeavor is partially selfish as I was thinking trying out the Sabaj a20d 2022, but the experience you and others are having with USB-C to USB-C connections gave me pause). I found two USB-C to USB-C OTG cables that appear reputable and are available from a US retailer:
- DD ddHiFI TC05 (2021) manufacturer’s link - Audio46 link
- FiiO - LT-TC1 manufacturer’s link - Audio46 link
The former has some reviews of it being used with an iPad and a Fiio KA3 (but does not specify which model iPad). The latter doesn’t have any reviews. Hopefully one or both of them will provide a single-cable solution. If you’re happy with the adapter, I would stick with that as it’s a known, working setup, but one of these cables might be worth the chance.